The storyline is at times muddled and incoherent. This won't bother readers much since they have the "inside track" on what's happening. Then again, the narrative is so predictable that maybe it doesn't matter.

Parents need to know that The Mortal Instruments: City of Bones is based on Cassandra Clare's best-selling urban fantasy series about warriors, demons, vampires, and werewolves and is the first film in a proposed action-fantasy franchise. Expect a lot of violent confrontations in the movie -- mostly using special blades and swords -- including scenes of torture and even death. Language is mild ("damn," "what the hell," etc.), and romance is limited to longing looks, a big kiss, and some sexy outfits. Like the book it's based on, the movie features a diverse cast and a brave female protagonist.

Families can talk about page-to-screen adaptations. How does The Mortal Instruments: City of Bones compare to the book? What are the main differences? What scenes from the book did you miss?

There's a lot of violence in the storytelling here. How do you think the peril compared to other young adult-based films like Twilight or The Hunger Games?

There's a theme that "all the stories are true" -- except for zombies. Which supernatural stories or creatures do you wish actually existed?

The good stuff

Messages: Like the book, the movie stresses the bravery of teens, the importance of adolescent friendships, and the difficulty (but necessity) of being open about your true self. It also explores how family is more than a connection by blood.

Role models: Clary and Simon are incredibly brave in the face of danger. The Shadowhunters -- Jace, Alec, Isabel -- are all courageous, but they've been trained as warriors. Magnus is a "downworlder" warlock, but he still helps the Shadowhunters when they need it. Clary's mother was determined to keep her safe and hidden from supernatural forces. The cast is notably diverse.

What to watch for

Violence: Lots of Shadowhunter-on-demon violence, and a couple of the demons are particularly frightening and gross. The Shadowhunters use blades and swords of all sizes (kindjals, chakrams, regular hand knives), as well as spears, vampire guns, and more. A swarm of vampires tries to kill or bite Clary and her friends and manages to land a bite on one unsuspecting character. Werewolves bite and kill demons; the villain and his thugs torture people, and several people come to blows. The body count includes several "extras." A major character is nearly killed, while others are seriously injured.

Sex: Clary and Jace gaze at each other longingly and eventually share a long kiss. Magnus Bane wears a revealing outfit (blazer, no shirt, boxer briefs) and flirts with Alec. A family secret alludes to the possibility of a forbidden relationship.

Language: Language includes "damn," "what the hell," "shut up," "crazy," and use of the word "mundane" as if it's pejorative, as well as "oh my God" and "Jesus" (as an exclamation).

Consumerism: A major character drives a Dodge Ram, an iPhone rings in several key scenes, there's a fight in front of a Rue 21, and Clary uses an Apple MacBook.

Drinking, drugs and smoking: There's drinking at a warlock's party, where vampires spike the drink of a human partygoer with a sort of debilitating liquid.

Movies.com, the ultimate source for everything movies, is your destination for new movie trailers, reviews, photos, times, tickets + more! Stay in the know with the latest movie news and cast interviews at Movies.com.